AD8264-EVALZ

Quad, 235 MHz, DC-Coupled VGA and Differential Output Amplifier AD8264 Data Sheet FEATURES GENERAL DESCRIPTION Low noise Voltage noise: 2.3 nV/√Hz Current noise: 2 pA/√Hz Wide bandwidth Small signal: 235 MHz (VGAx); 80 MHz (output amplifier) Large signal: 80 MHz (1 V p-p) Gain range 0 to 24 dB (input to VGA output) 6 to 30 dB (input to differential output) Gain scaling: 20 dB/V DC-coupled Single-ended input and differential output Supplies: ±2.5 V to ±5 V Low power: 140 mW per channel at ±3.3 V The AD8264 is a quad, linear-in-dB, general-purpose, variable gain amplifier (VGA) with a preamplifier (preamp), and a flexible differential output buffer. DC coupling, combined with wide bandwidth, makes this amplifier a very good pulse processor. Each channel includes a single-ended input preamp/VGA section to preserve the wide bandwidth and fast slew rate for low distortion pulse applications. A 6 dB differential output buffer with common-mode and offset adjustments enable direct coupling to most modern high speed analog-to-digital converters (ADCs), using the converter reference output for perfect dc matching levels. The −3 dB bandwidth of the preamp/VGA is dc to 235 MHz, and the bandwidth of the differential driver is 80 MHz. The floating gain control interface provides a precise linear-in-dB scale of 20 dB/V and is easy to interface to a variety of external circuits. The gain of each channel is adjusted independently, and all channels are referenced to a single pin, GNLO. Combined with a multioutput, digital-to-analog converter (DAC), each section of the AD8264 can be used for active calibration or as a trim amplifier. APPLICATIONS Multichannel data acquisition Positron emission tomography Gain trim Industrial and medical ultrasound Radar receivers Operation from a bipolar power supply enables amplification of negative voltage pulses generated by current-sinking pulses into a grounded load, such as is typical of photodiodes or photomultiplier tubes (PMT). Delay-free processing of wideband video signals is also possible. FUNCTIONAL BLOCK DIAGRAM ONE CHANNEL SHOWN OPPx VGAx PREAMP 6dB (2×) FIXED GAIN VGA AMPLIFIER 18dB (8×) DIFFERENTIAL OUTPUT AMPLIFIER 6dB (2×) IPPx IPNx 1kΩ 100Ω 100Ω VPOS VNEG + ATTENUATOR – –24dB TO 0dB INTERPOLATOR 2kΩ 747Ω GAIN INTERFACE VOLx 107Ω VOHx 2kΩ BIAS COMM GNHx GNLO VOCM OFSx 07736-001 1kΩ Figure 1. Rev. C Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 ©2009–2018 Analog Devices, Inc. All rights reserved. Technical Support www.analog.com AD8264 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Overview ..................................................................................... 28 Applications ....................................................................................... 1 Preamp ......................................................................................... 28 General Description ......................................................................... 1 VGA ............................................................................................. 28 Functional Block Diagram .............................................................. 1 Post Amplifier ............................................................................. 29 Revision History ............................................................................... 2 Noise ............................................................................................ 29 Specifications..................................................................................... 3 Applications Information .............................................................. 30 Absolute Maximum Ratings............................................................ 6 Thermal Resistance ...................................................................... 6 A Low Channel Count Application Concept Using a Discrete Reference ..................................................................................... 30 Maximum Power Dissipation ..................................................... 6 A DC Connected Concept Example ........................................ 31 ESD Caution .................................................................................. 6 Evaluation Board ............................................................................ 34 Pin Configuration and Function Descriptions ............................. 7 Connecting and Using the AD8264-EVALZ .......................... 34 Typical Performance Characteristics ............................................. 8 Outline Dimensions ....................................................................... 37 Test Circuits ..................................................................................... 20 Ordering Guide .......................................................................... 37 Theory of Operation ...................................................................... 28 REVISION HISTORY 10/2018—Rev. B to Rev. C Deleted Figure 113.......................................................................... 31 Added Figure 113; Renumbered Sequentially ............................ 31 Updated Outline Dimensions ....................................................... 37 1/2016—Rev. A to Rev. B Changes to Features Section, General Description Section, and Figure 1 .............................................................................................. 1 Changes to Figure 2 .......................................................................... 7 Changes to VGA Section ............................................................... 28 Updated Outline Dimensions ....................................................... 37 Changes to Ordering Guide .......................................................... 37 1/2011—Rev. 0 to Rev. A Changes to Figure 1 ...........................................................................1 Changes to Connecting and Using the AD8264-EVALZ Section and Figure 117 ................................................................................ 34 Changes to Figure 118 ................................................................... 35 5/2009—Revision 0: Initial Version Rev. C | Page 2 of 37 Data Sheet AD8264 SPECIFICATIONS VS = ±2.5 V, TA = 25°C, f = 10 MHz, CL = 5 pF, RL = 500 Ω per output (VGAx, VOHx, VOLx), VGAIN = (VGNHx − VGNLO) = 0 V, VVOCM = GND, VOFSx = GND, gain range = 6 dB to 30 dB, unless otherwise specified. Table 1. Parameter GENERAL PERFORMANCE –3 dB Small Signal Bandwidth (VGAx) –3 dB Large Signal Bandwidth (VGAx) –3 dB Small Signal Bandwidth (Differential Output)1 –3 dB Large Signal Bandwidth (Differential Output)1 Slew Rate Input Bias Current Input Resistance Input Capacitance Input Impedance Input Voltage Noise Input Current Noise Noise Figure (Differential Output) Output-Referred Noise (Differential Output) Output Impedance Output Signal Range Output Offset Voltage DYNAMIC PERFORMANCE Harmonic Distortion HD2 HD3 HD2 HD3 HD2 HD3 HD2 HD3 HD2 HD3 HD2 HD3 Input 1 dB Compression Point Test Conditions/Comments VOUT = 10 mV p-p VOUT = 1 V p-p VOUT = 100 mV p-p VOUT = 2 V p-p VGAx, VOUT = 2 V p-p VGAx, VOUT = 1 V p-p Differential output, VOUT = 2 V p-p Differential output, VOUT = 1 V p-p Pins IPPx Pins IPPx at dc; ΔVIN/ΔIBIAS Pins IPPx Pins IPPx at 10 MHz VGAIN = 0.7 V, RS = 50 Ω, unterminated VGAIN = 0.7 V (Gain = 30 dB) VGAIN = −0.7 V (Gain = 6 dB) VGAx, dc to 10 MHz Differential output, dc to 10 MHz Preamp VGAx, RL ≥ 500 Ω Differential amplifier, RL ≥ 500 Ω per side Preamp offset VGAx offset, VGAIN = 0.7 V Differential output offset, VGAIN = 0.7 V VGAx = 1 V p-p, differential output = 2 V p-p (measured at VGAx) f = 1 MHz f = 10 MHz f = 35 MHz VGAx = 1 V p-p, differential output = 2 V p-p (measured at differential output) f = 1 MHz f = 10 MHz f = 35 MHz VGAIN = −0.7 V, f = 10 MHz VGAIN = +0.7 V, f = 10 MHz Rev. C | Page 3 of 37 Min −8 −6 −18 −38 Typ 235 150 80 80 380 290 470 220 −5 4.2 2 7.9 2.3 2 9 72 45 3.5